1. The Field of the Invention
This invention relates generally to reduction in bone mass associated with inactivity, such as occurs whenever a limb is immobilized by a cast for an extended period of time, and more particularly to apparatus and methods to promote exercise on a cellular level when actual exercise motion by the limb is not available.
2. The Background Art
Bones represent a curious structure, often referred to in the prior art as “not well understood.” In space, such as during missions to the moon, extended orbits, work within the space station, during healing of a broken bone immobilized in a cast for typically six weeks or more, and the like, science has studied the loss of bone mass. The lack of exercise appears to relate to the loss of bone mass.
Moreover, bone mass may be lost at a greater rate in the absence of exercise then it can typically be regained upon resumption of exercise. Thus, what is needed is an apparatus and method to apply exercise to a bone structure that is immobilized as a result of casting, traction, immobilization, or the like.